Polyvariant estimation of possible climatologic river runoff changes with emphasis on the Northern Dvina catchment

Rivers of the Northern Dvina catchment are considered to demonstrate the possibility of obtaining polyvariant estimates of changes in the water regime of rivers in the northern part of the forest zone, which are caused by expected changes in air temperature and precipitation. For this purpose, the dynamic-stochastic modeling approach was applied. The snowmelt and rainfall runoff model developed at the Hydrometeorological Research Center of the Russian Federation was used as a hydrological unit. Meteorological observational data collected during the 50- to 60-year period were statistically expanded by using an approach based on composing artificial variants of the annual cycle of meteorological variables, which can be performed through combining the observed variants of weather conditions of the cold and warm periods. As a result, polyvariant estimates of possible changes in the water regime of rivers corresponding to various scenarios of changes in air temperature and precipitation were obtained.